Publications by authors named "David R Montgomery"

21 Publications

  • Page 1 of 1

Soil health and nutrient density: preliminary comparison of regenerative and conventional farming.

PeerJ 2022 27;10:e12848. Epub 2022 Jan 27.

Brown's Ranch, Bismarck, ND, USA.

Several independent comparisons indicate regenerative farming practices enhance the nutritional profiles of crops and livestock. Measurements from paired farms across the United States indicate differences in soil health and crop nutrient density between fields worked with conventional (synthetically-fertilized and herbicide-treated) or regenerative practices for 5 to 10 years. Specifically, regenerative farms that combined no-till, cover crops, and diverse rotations-a system known as Conservation Agriculture-produced crops with higher soil organic matter levels, soil health scores, and levels of certain vitamins, minerals, and phytochemicals. In addition, crops from two regenerative no-till vegetable farms, one in California and the other in Connecticut, had higher levels of phytochemicals than values reported previously from New York supermarkets. Moreover, a comparison of wheat from adjacent regenerative and conventional no-till fields in northern Oregon found a higher density of mineral micronutrients in the regenerative crop. Finally, a comparison of the unsaturated fatty acid profile of beef and pork raised on one of the regenerative farms to a regional health-promoting brand and conventional meat from local supermarkets, found higher levels of omega-3 fats and a more health-beneficial ratio of omega-6 to omega-3 fats. Despite small sample sizes, all three crop comparisons show differences in micronutrient and phytochemical concentrations that suggest soil health is an under appreciated influence on nutrient density, particularly for phytochemicals not conventionally considered nutrients but nonetheless relevant to chronic disease prevention. Likewise, regenerative grazing practices produced meat with a better fatty acid profile than conventional and regional health-promoting brands. Together these comparisons offer preliminary support for the conclusion that regenerative soil-building farming practices can enhance the nutritional profile of conventionally grown plant and animal foods.
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http://dx.doi.org/10.7717/peerj.12848DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8801175PMC
January 2022

Evidence for repeated failure of the giant Yigong landslide on the edge of the Tibetan Plateau.

Sci Rep 2020 09 1;10(1):14371. Epub 2020 Sep 1.

Institute of Geomechanics, Chinese Academy of Geological Sciences, Beijing, 100081, China.

Field surveys and radiocarbon dating of detrital materials provide evidence that repeated landslides dammed the Yigong Tsangpo River ca. 3500 BC, 1300 BC, 1000 BC, 600 BC, and twice more recently. Together with historical slides in 1900 and 2000, these six older slides make for a total of eight known channel-damming landslide events at the same location over the past six millennia, indicating sub-millennia recurrence intervals over this time period. Together with the likely incomplete nature of the sedimentary record of past channel-damming episodes uncovered to date, our findings indicate late Holocene multi-century-scale recurrence intervals for large landslides at this location. Hence, the riverbed at and immediately upstream of this location may have been inundated by sediment, and therefore not incising, for much of the post-glacial period. Together with the location of this landslide complex at the head of the major knickzone defining the fluvial edge of the Tibetan Plateau, our findings support the hypothesis that repeated glacial and landslide damming in this region inhibited headward propagation of river incision into the Tibetan Plateau.
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http://dx.doi.org/10.1038/s41598-020-71335-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7463243PMC
September 2020

Lessons from a pandemic on practices versus products in agriculture.

Agric Human Values 2020 13;37(3):617-618. Epub 2020 May 13.

www.Dig2Grow.com, Seattle, USA.

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http://dx.doi.org/10.1007/s10460-020-10102-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7218700PMC
May 2020

Extra Nodal Rosai-Dorfman Disease Originating in the Nasal and Paranasal Complex and Gnathic Bones: A Systematic Analysis of Seven Cases and Review of Literature.

Head Neck Pathol 2020 Jun 31;14(2):442-453. Epub 2019 Jul 31.

Oral Pathology Consultants, St. Joseph Mercy-Oakland Hospital, Pontiac, MI, 48341, USA.

Rosai-Dorfman disease (RDD) is a benign, self-limiting histiocytosis of unknown etiology. The classic form of the condition includes a painless cervical lymphaenopathy accompanied by fever, weight loss and an elevated ESR. Extra nodal RDD (ENRDD) is most frequent in the head and neck. Thirty-eight cases of ENRDD have been described. Seven cases of ENRDD were identified in our pathology biopsy services. The demographic and clinical information was tabulated logically on the basis of age, gender, location and presence or absence of symptoms, treatment and follow-up. Radiographic and histopathological features were also examined. The findings in these cases were correlated with those available from the previously reported cases. Six cases affected women and one case was diagnosed in a male. The age ranged from 22-55 years. Three cases presented as a nasal mass. One of these lesions extended into the paranasal sinuses. One case was located in the maxilla and extended to involve the maxillary sinus. Three cases were diagnosed in the mandible. The maxillary and one mandibular lesion (Case 2) resulted in significant painful irregular bone destruction with a non-healing socket and tooth mobility respectively. One mandibular lesion was asymptomatic (Case 6). The third case affecting the mandible presented as a rapidly expansile mass following a tooth extraction (Case 7). Nasal masses presented with symptoms of obstruction. Nasal masses were excised with no recurrence from up to 2-3 years of follow-up. The mandibular lesions were curetted aggressively. The oral mass in Case 7 was excised synchronously. No recurrence up to 2 years was recorded in Case 2. Follow-up information is not available for Cases 6 and 7. The maxillary lesion was not intervened surgically. The patient has persistent but stable disease for a follow-up period of 2 years. ENRDD is rarely considered in the differential diagnosis in the absence of lymph node involvement. Lesions of ENRDD resemble many other histiocytic and histiocyte-rich lesions of the head and neck. This makes the diagnosis of ENRDD challenging with the potential for under diagnosis or misdiagnosis and delay in treatment.
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http://dx.doi.org/10.1007/s12105-019-01056-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7235143PMC
June 2020

Anthropogenic strath terrace formation caused by reduced sediment retention.

Proc Natl Acad Sci U S A 2019 04 15;116(18):8734-8739. Epub 2019 Apr 15.

Department of Earth and Space Sciences, University of Washington, Seattle, WA 98195.

Across North America, human activities have been shown to cause river incision into unconsolidated alluvium. Human-caused erosion through bedrock, however, has only been observed in local and isolated outcrops. Here, we test whether splash-dam logging, which decreased in-stream alluvial cover by removing much of the alluvium-trapping wood, caused basin-wide bedrock river incision in a forested mountain catchment in Washington State. We date incision of the youngest of four strath terraces, using dendrochronology and radiocarbon, to between 1893 CE and 1937 CE in the Middle Fork Teanaway River and 1900 CE and 1970 CE in the West Fork Teanaway River, coincident with timber harvesting and splash damming in the basins. Other potential drivers of river incision lack a recognized mechanism to cause T1 incision or are not synchronous with T1 incision. Hence, the close temporal correspondence suggests that reduced sediment retention triggered by splash damming led to the observed 1.1 mm⋅y to 23 mm⋅y of bedrock river incision and reduction of the active floodplain to 20% and 53% of its preincision extent on the Middle and West Forks, respectively. The development of such anthropogenic bedrock terraces may be an emerging, globally widespread physiographic signature of the Anthropocene.
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http://dx.doi.org/10.1073/pnas.1814627116DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6500176PMC
April 2019

ANTHROPOLOGY. Emperor Yu's Great Flood.

Science 2016 Aug;353(6299):538-9

Earth and Space Sciences, University of Washington, Seattle, WA 98195, USA.

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http://dx.doi.org/10.1126/science.aah4040DOI Listing
August 2016

Glaciated valleys in Europe and western Asia.

J Maps 2015 Mar 23;11(2):361-370. Epub 2014 May 23.

Department of Geography, University of Bonn , Bonn , Germany.

In recent years, remote sensing, morphometric analysis, and other computational concepts and tools have invigorated the field of geomorphological mapping. Automated interpretation of digital terrain data based on impartial rules holds substantial promise for large dataset processing and objective landscape classification. However, the geomorphological realm presents tremendous complexity and challenges in the translation of qualitative descriptions into geomorphometric semantics. Here, the simple, conventional distinction of V-shaped fluvial and U-shaped glacial valleys was analyzed quantitatively using multi-scale curvature and a novel morphometric variable termed Difference of Minimum Curvature (DMC). We used this automated terrain analysis approach to produce a raster map at a scale of 1:6,000,000 showing the distribution of glaciated valleys across Europe and western Asia. The data set has a cell size of 3 arc seconds and consists of more than 40 billion grid cells. Glaciated U-shaped valleys commonly associated with erosion by warm-based glaciers are abundant in the alpine regions of mid Europe and western Asia but also occur at the margins of mountain ice sheets in Scandinavia. The high-level correspondence with field mapping and the fully transferable semantics validate this approach for automated analysis of yet unexplored terrain around the globe and qualify for potential applications on other planetary bodies like Mars.
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http://dx.doi.org/10.1080/17445647.2014.921647DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4786831PMC
March 2015

Tectonic control on the persistence of glacially sculpted topography.

Nat Commun 2015 Aug 14;6:8028. Epub 2015 Aug 14.

Department of Earth and Space Sciences, University of Washington, Johnson Hall, 4000 15th Avenue NE, Seattle, Washington 98195, USA.

One of the most fundamental insights for understanding how landscapes evolve is based on determining the extent to which topography was shaped by glaciers or by rivers. More than 10(4) years after the last major glaciation the topography of mountain ranges worldwide remains dominated by characteristic glacial landforms such as U-shaped valleys, but an understanding of the persistence of such landforms is lacking. Here we use digital topographic data to analyse valley shapes at sites worldwide to demonstrate that the persistence of U-shaped valleys is controlled by the erosional response to tectonic forcing. Our findings indicate that glacial topography in Earth's most rapidly uplifting mountain ranges is rapidly replaced by fluvial topography and hence valley forms do not reflect the cumulative action of multiple glacial periods, implying that the classic physiographic signature of glaciated landscapes is best expressed in, and indeed limited by, the extent of relatively low-uplift terrain.
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http://dx.doi.org/10.1038/ncomms9028DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4557346PMC
August 2015

Multi-scale curvature for automated identification of glaciated mountain landscapes.

Geomorphology (Amst) 2014 Mar;209(100):53-65

Department of Geography, University of Bonn, 53115 Bonn, Germany.

Erosion by glacial and fluvial processes shapes mountain landscapes in a long-recognized and characteristic way. Upland valleys incised by fluvial processes typically have a V-shaped cross-section with uniform and moderately steep slopes, whereas glacial valleys tend to have a U-shaped profile with a changing slope gradient. We present a novel regional approach to automatically differentiate between fluvial and glacial mountain landscapes based on the relation of multi-scale curvature and drainage area. Sample catchments are delineated and multiple moving window sizes are used to calculate per-cell curvature over a variety of scales ranging from the vicinity of the flow path at the valley bottom to catchment sections fully including valley sides. Single-scale curvature can take similar values for glaciated and non-glaciated catchments but a comparison of multi-scale curvature leads to different results according to the typical cross-sectional shapes. To adapt these differences for automated classification of mountain landscapes into areas with V- and U-shaped valleys, curvature values are correlated with drainage area and a new and simple morphometric parameter, the Difference of Minimum Curvature (), is developed. At three study sites in the western United States the thresholds determined from catchment analysis are used to automatically identify 5 × 5 km quadrats of glaciated and non-glaciated landscapes and the distinctions are validated by field-based geological and geomorphological maps. Our results demonstrate that is a good predictor of glacial imprint, allowing automated delineation of glacially and fluvially incised mountain landscapes.
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http://dx.doi.org/10.1016/j.geomorph.2013.11.026DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3991310PMC
March 2014

Rapid soil production and weathering in the Southern Alps, New Zealand.

Science 2014 Feb 16;343(6171):637-40. Epub 2014 Jan 16.

Department of Earth and Space Sciences and Quaternary Research Center, University of Washington, Seattle, WA 98195-1310, USA.

Evaluating conflicting theories about the influence of mountains on carbon dioxide cycling and climate requires understanding weathering fluxes from tectonically uplifting landscapes. The lack of soil production and weathering rate measurements in Earth's most rapidly uplifting mountains has made it difficult to determine whether weathering rates increase or decline in response to rapid erosion. Beryllium-10 concentrations in soils from the western Southern Alps, New Zealand, demonstrate that soil is produced from bedrock more rapidly than previously recognized, at rates up to 2.5 millimeters per year. Weathering intensity data further indicate that soil chemical denudation rates increase proportionally with erosion rates. These high weathering rates support the view that mountains play a key role in global-scale chemical weathering and thus have potentially important implications for the global carbon cycle.
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http://dx.doi.org/10.1126/science.1244908DOI Listing
February 2014

A process-based hierarchical framework for monitoring glaciated alpine headwaters.

Environ Manage 2012 Dec 12;50(6):982-97. Epub 2012 Oct 12.

Natural Systems Design, Seattle, WA, USA.

Recent studies have demonstrated the geomorphic complexity and wide range of hydrologic regimes found in alpine headwater channels that provide complex habitats for aquatic taxa. These geohydrologic elements are fundamental to better understand patterns in species assemblages and indicator taxa and are necessary to aquatic monitoring protocols that aim to track changes in physical conditions. Complex physical variables shape many biological and ecological traits, including life history strategies, but these mechanisms can only be understood if critical physical variables are adequately represented within the sampling framework. To better align sampling design protocols with current geohydrologic knowledge, we present a conceptual framework that incorporates regional-scale conditions, basin-scale longitudinal profiles, valley-scale glacial macroform structure, valley segment-scale (i.e., colluvial, alluvial, and bedrock), and reach-scale channel types. At the valley segment- and reach-scales, these hierarchical levels are associated with differences in streamflow and sediment regime, water source contribution and water temperature. Examples of linked physical-ecological hypotheses placed in a landscape context and a case study using the proposed framework are presented to demonstrate the usefulness of this approach for monitoring complex temporal and spatial patterns and processes in glaciated basins. This approach is meant to aid in comparisons between mountain regions on a global scale and to improve management of potentially endangered alpine species affected by climate change and other stressors.
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http://dx.doi.org/10.1007/s00267-012-9957-8DOI Listing
December 2012

Glacier and landslide feedbacks to topographic relief in the Himalayan syntaxes.

Proc Natl Acad Sci U S A 2010 Mar 8;107(12):5317-22. Epub 2010 Mar 8.

Swiss Federal Research Institutes WSL/SLF, Flüelastr. 11, CH-7260 Davos, Switzerland.

Despite longstanding research on the age and formation of the Tibetan Plateau, the controls on the erosional decay of its margins remain controversial. Pronounced aridity and highly localized rock uplift have traditionally been viewed as limits to the dissection of the plateau by bedrock rivers. Recently, however, glacier dynamics and landsliding have been argued to retard headward fluvial erosion into the plateau interior by forming dams and protective alluvial fill. Here, we report a conspicuous clustering of hundreds of natural dams along the Indus and the Tsangpo Rivers where these cross the Himalayan syntaxes. The Indus is riddled by hundreds of dams composed of debris from catastrophic rock avalanches, forming the largest concentration of giant landslide dams known worldwide, whereas the Tsangpo seems devoid of comparable landslide dams. In contrast, glacial dams such as river-blocking moraines in the headwaters of both rivers are limited to where isolated mountain ranges intersect the regional snowline. We find that to first-order, high local topographic relief along both rivers corresponds to conspicuously different knickzones and differences in the type and potential longevity of these dams. In both syntaxes, glacier and landslide dams act as a negative feedback in response to fluvial dissection of the plateau margins. Natural damming protects bedrock from river incision and delays headward knickpoint migration, thereby helping stabilize the southwestern and southeastern margins of the Tibetan Plateau in concert with the effects of upstream aridity and localized rock uplift.
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http://dx.doi.org/10.1073/pnas.0907531107DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2851790PMC
March 2010

Tibetan plateau river incision inhibited by glacial stabilization of the Tsangpo gorge.

Nature 2008 Oct;455(7214):786-9

Swiss Federal Research Institutes WSL/SLF, Flüelastr. 11, CH-7260 Davos, Switzerland.

A considerable amount of research has focused on how and when the Tibetan plateau formed in the wake of tectonic convergence between India and Asia. Although far less enquiry has addressed the controls on river incision into the plateau itself, widely accepted theory predicts that steep fluvial knick points (river reaches with very steep gradients) in the eastern Himalayan syntaxis at the southeastern plateau margin should erode rapidly, driving a wave of incision back into the plateau. Preservation of the plateau edge thus presents something of a conundrum that may be resolved by invoking either differential rock uplift matching erosional decay, or other mechanisms for retarding bedrock river incision in this region where high stream power excludes the potential for aridity as a simple limit to dissection of the plateau. Here we report morphologic evidence showing that Quaternary depression of the regional equilibrium line altitude, where long-term glacier mass gain equals mass loss, was sufficient to repeatedly form moraine dams on major rivers: such damming substantially impeded river incision into the southeastern edge of the Tibetan plateau through the coupled effects of upstream impoundment and interglacial aggradation. Such glacial stabilization of the resulting highly focused river incision centred on the Tsangpo gorge could further contribute to initiating and accentuating a locus of rapid exhumation, known as tectonic anaeurysm.
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http://dx.doi.org/10.1038/nature07322DOI Listing
October 2008

Protecting the soil beneath. Interview by Naomi Lubick.

Environ Sci Technol 2008 May;42(9):3129-32

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http://dx.doi.org/10.1021/es087046tDOI Listing
May 2008

Geology. Dreams of natural streams.

Science 2008 Jan;319(5861):291-2

Department of Earth and Space Sciences, Quaternary Research Center, University of Washington, Seattle, WA 98195, USA.

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http://dx.doi.org/10.1126/science.1153480DOI Listing
January 2008

Channel and perennial flow initiation in headwater streams: management implications of variability in source-area size.

Environ Manage 2007 Nov 28;40(5):775-86. Epub 2007 Sep 28.

College of Forest Resources, University of Washington, Seattle, WA, 98195-2100, USA.

Despite increasing attention to management of headwater streams as sources of water, sediment, and wood to downstream rivers, the extent of headwater channels and perennial flow remain poorly known and inaccurately depicted on topographic maps and in digital hydrographic data. This study reports field mapping of channel head and perennial flow initiation locations in forested landscapes underlain by sandstone and basalt lithologies in Washington State, USA. Contributing source areas were delineated for each feature using a digital elevation model (DEM) as well as a Global Positioning System device in the field. Systematic source area-slope relationships described in other landscapes were not evident for channel heads in either lithology. In addition, substantial variability in DEM-derived source area sizes relative to field-delineated source areas indicates that in this area, identification of an area-slope relationship, should one even exist, would be difficult. However, channel heads and stream heads, here defined as the start of perennial flow, appear to be co-located within both of the lithologies, which together with lateral expansion and contraction of surface water around channel heads on a seasonal cycle in the basalt lithology, suggest a controlling influence of bedrock springs for that location. While management strategies for determining locations of channel heads and perennial flow initiation in comparable areas could assign standard source area sizes based on limited field data collection within that landscape, field-mapped source areas that support perennial flow are much smaller than recognized by current Washington State regulations.
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http://dx.doi.org/10.1007/s00267-005-0311-2DOI Listing
November 2007

Soil erosion and agricultural sustainability.

Proc Natl Acad Sci U S A 2007 Aug 8;104(33):13268-72. Epub 2007 Aug 8.

Department of Earth and Space Sciences, University of Washington, Seattle, WA 91895, USA.

Data drawn from a global compilation of studies quantitatively confirm the long-articulated contention that erosion rates from conventionally plowed agricultural fields average 1-2 orders of magnitude greater than rates of soil production, erosion under native vegetation, and long-term geological erosion. The general equivalence of the latter indicates that, considered globally, hillslope soil production and erosion evolve to balance geologic and climate forcing, whereas conventional plow-based agriculture increases erosion rates enough to prove unsustainable. In contrast to how net soil erosion rates in conventionally plowed fields ( approximately 1 mm/yr) can erode through a typical hillslope soil profile over time scales comparable to the longevity of major civilizations, no-till agriculture produces erosion rates much closer to soil production rates and therefore could provide a foundation for sustainable agriculture.
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http://dx.doi.org/10.1073/pnas.0611508104DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1948917PMC
August 2007

Planetary science: are there active glaciers on Mars?

Nature 2005 Dec;438(7069):E9-10; discussion E10

Quaternary Research Center and Department of Earth and Space Sciences, University of Washington, Seattle, Washington 98195-1310, USA.

Head et al. interpret spectacular images from the Mars Express high-resolution stereo camera as evidence of geologically recent rock glaciers in Tharsis and of a piedmont ('hourglass') glacier at the base of a 3-km-high massif east of Hellas. They attribute growth of the low-latitude glaciers to snowfall during periods of increased spin-axis obliquity. The age of the hourglass glacier, considered to be inactive and slowly shrinking beneath a debris cover in the absence of modern snowfall, is estimated to be more than 40 Myr. Although we agree that the maximum glacier extent was climatically controlled, we find evidence in the images to support local augmentation of accumulation from snowfall through a mechanism that does not require climate change on Mars.
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http://dx.doi.org/10.1038/nature04357DOI Listing
December 2005

Coupled spatial variations in precipitation and long-term erosion rates across the Washington Cascades.

Nature 2003 Dec;426(6967):645-7

Department of Geology and Geophysics, Yale University, 210 Whitney Avenue, New Haven, Connecticut 06511, USA.

Past studies of tectonically active mountain ranges have suggested strong coupling and feedbacks between climate, tectonics and topography. For example, rock uplift generates topographic relief, thereby enhancing precipitation, which focuses erosion and in turn influences rates and spatial patterns of further rock uplift. Although theoretical links between climate, erosion and uplift have received much attention, few studies have shown convincing correlations between observable indices of these processes on mountain-range scales. Here we show that strongly varying long-term (>10(6)-10(7) yr) erosion rates inferred from apatite (U-Th)/He cooling ages across the Cascades mountains of Washington state closely track modern mean annual precipitation rates. Erosion and precipitation rates vary over an order of magnitude across the range with maxima of 0.33 mm yr(-1) and 3.5 m yr(-1), respectively, with both maxima located 50 km west (windward) of the topographic crest of the range. These data demonstrate a strong coupling between precipitation and long-term erosion rates on the mountain-range scale. If the range is currently in topographic steady state, rock uplift on the west flank is three to ten times faster than elsewhere in the range, possibly in response to climatically focused erosion.
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http://dx.doi.org/10.1038/nature02111DOI Listing
December 2003

Episodic sediment accumulation on Amazonian flood plains influenced by El Niño/Southern Oscillation.

Nature 2003 Oct;425(6957):493-7

Quaternary Research Center University of Washington, Seattle, Washington 98195, USA.

Continental-scale rivers with a sandy bed sequester a significant proportion of their sediment load in flood plains. The spatial extent and depths of such deposits have been described, and flood-plain accumulation has been determined at decadal timescales, but it has not been possible to identify discrete events or to resolve deposition on near-annual timescales. Here we analyse (210)Pb activity profiles from sediment cores taken in the pristine Beni and Mamore river basins, which together comprise 720,000 km2 of the Amazon basin, to investigate sediment accumulation patterns in the Andean-Amazonian foreland. We find that in most locations, sediment stratigraphy is dominated by discrete packages of sediments of uniform age, which are typically 20-80 cm thick, with system-wide recurrence intervals of about 8 yr, indicating relatively rare episodic deposition events. Ocean temperature and stream flow records link these episodic events to rapidly rising floods associated with La Niña events, which debouch extraordinary volumes of sediments from the Andes. We conclude that transient processes driven by the El Niño/Southern Oscillation cycle control the formation of the Bolivian flood plains and modulate downstream delivery of sediments as well as associated carbon, nutrients and pollutants to the Amazon main stem.
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http://dx.doi.org/10.1038/nature02002DOI Listing
October 2003

Streamflow and water well responses to earthquakes.

Science 2003 Jun;300(5628):2047-9

Department of Earth and Space Sciences, University of Washington, Seattle, WA 98195, USA.

Earthquake-induced crustal deformation and ground shaking can alter stream flow and water levels in wells through consolidation of surficial deposits, fracturing of solid rocks, aquifer deformation, and the clearing of fracture-filling material. Although local conditions affect the type and amplitude of response, a compilation of reported observations of hydrological response to earthquakes indicates that the maximum distance to which changes in stream flow and water levels in wells have been reported is related to earthquake magnitude. Detectable streamflow changes occur in areas within tens to hundreds of kilometers of the epicenter, whereas changes in groundwater levels in wells can occur hundreds to thousands of kilometers from earthquake epicenters.
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http://dx.doi.org/10.1126/science.1082980DOI Listing
June 2003
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